This topic flagged again for me, so I should update it.
I have been carrying the above 6.8 pretty much daily for the last several months. It did not end up in TX.... I ran out of time to zero the PEQ 15 on it.
Based on early use, I wanted a different optic, mostly because of size. I also noticed that I was mostly leaving the 2-7 on about 4x.
SpaceTaco sold me a TA01 ACOG recently which matches this rifle and cartridge to a tee. I have been splattering gophers with it in the 100 yard realm, and have dropped pepper poppers out to 400 with it. The ballistic function of the TA01 matches the 6.8 well enough for consistent hear shots at 400.
While it is equipped for a suppressor, I have typically run it loud for handling reasons.
I have run a hundred S&B FMJ rounds, a hundred American Eagle FMJ rounds and am just finishing the first of several boxes of Hornady SST. Both the SB and the AR rounds are apparently hot.... I was getting consistent ejector smears on the case head, suppressed and unsuppressed. The Hornady load eliminates the smearing and has excellent accuracy and terminal effects. It will group .75" to 1" under the TA01 at 100 meters, I am ordering a case of it going forward.
I am using PRI 15 and 25 round mags. The 15s get most use. I have been loading them with 14 so that they will seat easily under a closed bolt.
I set this rifle up with a simple Magpul MOE rifle stock. I am considering swapping to an A5 tube with the fixed MOE CTR type stock. I prefer the asthetic of the CTR and it should be slightly lighter, with about .5" less length of pull.
This rifle has worked out really well. I have not carried anything else lately. I am impressed with the 6.8.